We often have doubt of what was actually doing this program provided with all Google products. To clear this doubt, this note was published:

Since Google Update is always running on your system, there's no simple way to stop it, and since it's a fundamental part of the Google software that needs it, it's not explicitly installed. Some users can be surprised to find this program running, and at Google, we don't like disappointing our users. We've been working hard to address these concerns, and releasing the source code for Omaha is our attempt to make the purpose of Google Update totally transparent. Obviously, we understand that not everyone is both willing and able to read through our code, but we hope that those of you who do will confirm for the rest that Google Update's functionality serves well to keep your software up to date.